It was 4yrs old and over the last few months it wasn't cooling like it use too.
When I contacted Corsair support and told them that I ran a Aida64 Fpu test and the heat shot up to 81c in 1.5 mins into the test they immediately suggested a Rma.
They didn't say what actually happened but I think it had permeated.
Corsair warranties their coolers for 5yrs so that is 1 thing to think about is the warranty.
If a water cooler makes it past the warranty time hay cool but expect to replace anytime after that.
That's where air coolers have the advantage over water coolers less moving parts.
If fans go out or get noisy you can just replace them not the whole unit if a pump goes out.
Here is some info on water coolers for you
Which can help explain alot.
https://www.gamersnexus.net/guides/2926-how-liquid-coolers-work-deep-dive
And this for install watch this vid
Pay attention to the points that the pump should not be the highest point as air will make it way to the top of the system.
View: https://m.youtube.com/watch?v=BbGomv195sk
My coolers have always been top mounted as exhaust.
I not trying to tell you should or shouldn't go for water cooling but it's not totally hassle free if you want to maintain proper cooling.
If this unit is coming with a full manufacturers warranty then feel alot more at ease for your money.
If it's used then think about it long and hard
And
By all means Do Not get rid of your current cooler which ever way you go to have as backup.
My coolers where on the older fx platform and carried over to the Ryzen platform.
I currently have a Corsair H150i Elite Capellix 360mm on a 3600x oc'd to 4.325 ghz playing Ghost Recon Wildlands it stays at 58.8c on a custom curve ( acceptable temp vs noise)
This cooler Is my new 1.
The older unit was 2 months from the warranty end so while We Can't get GPU's in Stock or @ a Decent Price I decided to upgrade other parts of my system.
Old unit was Corsair H110i 280mm paired with Noctua IPPC's 3000rpm fans.
My son's is a Corsair H110i 280mm on a 3600 with a pair of noctua 140mm Ippc 3000rpm fans and has never had any issues.
My wife's unit was the older Corsair H100iv2 240mm on a 2600x
The Arctic esports 34 duo I put on is Super Quiet as she only plays facebook games so no real hardcore gaming from hers.
Hell I have to double check if her system is turned on or not it's that quiet.
That cooler I got off amazon for 48-50 bucks.
https://www.amazon.com/ARCTIC-Freezer-eSports-DUO-Configuration/dp/B0846LPTLD?th=1&psc=1
Like I said she's not into hardcore gaming
So this cooler is more the able to keep her system cool.
Be sure to check your case for where you can mount the cooler and the size it can handle before buying that cooler.